The present invention relates generally to a bracket for attachment to a movable window and connection to an automotive window lifting mechanism, and relates more specifically to a window bracket having at least one flexible beam which engages the window.
In vehicles, and especially automobiles, it is highly desirable to have movable windows. With reference to automobiles, windows are displaceable upwardly and downwardly relative to a door assembly by use of a manual crank or an electrically-driven window lifting mechanism. Many window lifting mechanisms include a scissoring linkage which transfers motion from a manual crank or electric drive to a window connected to the window lifting mechanism. The scissoring linkage is used in order to limit the movement of the window in a generally vertical direction. A cross member is attached to the scissoring linkage to provide a support for the movable window. Such a window lifting mechanism is disclosed in U.S. Pat. No. 5,513,468, which is hereby incorporated herein by reference in its entirety.
Mounting brackets or window lift brackets are often used to attach the movable window to the cross member attached to the scissoring linkage. These brackets generally are attached to a mounting edge of the window at two spaced apart locations and a portion of the bracket is attached to the window lifting cross member.
Many prior art brackets present problems in a movable window assembly, are difficult to manufacture, and are relatively expensive. Some prior art brackets are manufactured from a stamped strip of metal which is deformed to a specified bracket configuration. These deformed metal components are subject to damage and failure as the result of corrosion thereby providing a weak link in the movable window assembly.
With regard to the manufacturing of such prior art window lift brackets, many opportunities for complications and defects arise. Initially, a strip of metal is stamped or cut to a desired size. Next, the metal component is stamped, bored or drilled to provide through holes which will be used as described here and below. The stamped metal component is deformed to form a bracket having a generally xe2x80x9cYxe2x80x9d shaped cross section. The deformed metal component must now be protected by painting, anodizing or other means to delay the corrosion process. Once protected, plastic mounted clips are positioned in a channel portion of the bracket and secured in the thru holes by use of a heat staking process. The base of the bracket is drilled for receiving a fastener which will be used to attach the bracket to the lift mechanism cross member.
In applying such prior art lift brackets to a window, an adhesive is disposed in the channel portion of the lift bracket and the lift bracket is attached to the mounted edge of a movable window. The window, with two or more brackets positioned thereon, is subjected to a heat curing process in order to cure the adhesive. A heat curing adhesive is used in order to properly adhere the adhesive to the surfaces of the bracket and window.
As may be understood from the description hereinabove, there are numerous opportunities for problems to arise in the manufacture of a window lift bracket as set forth by the prior art. For example, if the bracket is not properly formed, it may not properly fit on the window or function in the movable window assembly. In each step of the fabrication process a new operation, coating, or joining method is used, each presenting its own opportunity for problems.
For example, as mentioned, clips must be used with the deformed metal bracket in order to prevent the bracket from scratching the window glass and the protective coating on the window. The plastic clips are an individual piece part which must be designed, purchased, and managed in the manufacturing system. The clips are typically produced by selectively cutting an extruded plastic strip. Each clip must be cut to a generally precise dimension thereby requiring an additional inspection step. The clips must also be heat staked to the metal bracket. The heat staking process deforms a portion of the plastic clip over an abutting portion of the metal bracket. If the plastic portion is not properly melted, it may not be securely held to the metal bracket which could result in a release of the window from the bracket under certain circumstances. Clearly, it is not desirable to have a release of the window from the bracket.
Additionally, an adhesive is disposed in a channel portion of the metal bracket to secure the window to the bracket. The adhesive must be selected to attach or adhere to the metal bracket (or the protective surface of the metal bracket) and the window glass and/or coating. The numerous and diverse material properties involved can make selection of an appropriate adhesive somewhat difficult. Further, if the metal bracket begins to corrode, the corrosion could result in the adhesive detaching from the metal bracket.
As may be clear, there are numerous problems associated with the manufacture and use of metal window lift brackets as currently used in the prior art. As such, it is important to find a window lift bracket which will overcome the problems associated with the prior art devices.
A window lift bracket which overcomes many of the problems presented by some prior art window brackets can be found in U.S. Pat. No. 5,513,468, which has been incorporated herein in its entirety be reference hereinabove. The bracket which is disclosed in the ""468 patent is also generally illustrated in FIG. 1 of the present application, as is designated with reference numeral 10. The bracket 10 includes a base 12 which is configured for attachment to a window lifting mechanism (see FIG. 1 of the ""468 patent), and spaced apart sidewalls 14 which extend from the base 12 and define a channel 16 which receives an edge of the window (see FIGS. 1, 6 and 7 of the ""468 patent). Each of the sidewalls 14 includes alternating protrusions 17 and depressions 18 which define a convoluted surface.
As described in the ""468 patent, the convoluted surfaces increase the effective surface area of the inside surface of the sidewalls 14, thereby increasing the contact surface between an adhesive applied to the convoluted surfaces and the window which is disposed in the channel 16. As disclosed in the ""468 patent, the bracket 10 also includes a groove 19 at the bottom of the channel 16 which provides even greater holding forces between the adhesive and the window. As disclosed in the ""468 patent, the bracket 10 is preferably formed of a plastics material which allows the bracket to be integrally formed as a unitary, single-piece body. Such a configuration presents certain advantages, including certain manufacturing advantages.
While the bracket 10 disclosed in the ""468 patent and illustrated in FIG. 1 of the present application presents several advantages over many prior art window brackets, the bracket 10 also presents a disadvantage. Specifically, the bracket 10 is configured such that when the window is installed in the bracket 10, and specifically in the channel 19 defined by the sidewalls 14, an interference fit results between the sidewalls 14 and the window. The interference fit tends to create high stresses in the bottom of the channel 16, which may cause the bracket 10 to fail.
An embodiment of the present invention essentially provides an improvement to the bracket disclosed in the ""468 patent. Hence, the embodiment provides many of the same advantages as does the bracket disclosed in the ""468 patent, while being directed to overcome the noted disadvantage-namely, eliminating the high stress area which is present in the bottom of the channel of the bracket disclosed in the ""468 patent.
A general object of an embodiment of the present invention is to provide a window lift bracket which will securely attach to a window and a window lifting mechanism.
Another object of an embodiment of the present invention is to provide a window lift bracket with a reduced stress area.
A still further object of the present invention is to provide a window lift bracket which is efficiently manufactured and eliminates numerous manufacturing steps and the parts required to manufacture a bracket.
Briefly, and in accordance with at least one of the foregoing, an embodiment of the present invention envisions a window lift bracket for attachment to a mounting edge of a movable window and which is connectable to a window lifting mechanism. The window lift bracket includes a base which is attachable to the window lifting mechanism and spaced apart portions extending from the base being positionable on either side of the movable window. The spaced apart portions define a channel therebetween. The window lift bracket includes at least one member, such as a flexible beam member, which is disposed generally in the channel for engaging the window when the window is disposed therein. Preferably, the engagement between the member and the window provides a reduced stress area at the bottom of the channel. Opposing surfaces of the spaced apart portions may provide convoluted surfaces, such as protrusions and depressions, which effectively increase the surface area to which the adhesive adheres, thereby improving the adhesion of the adhesive to the window bracket and the window.